Cloud architectures are used in cloud computing and cloud storage systems for offering infrastructure-as-a-service (IaaS) cloud services. Examples of cloud architectures include the VMware vCloud Director® cloud architecture software, Amazon EC2™ web service, and OpenStack™ open source cloud computing service. IaaS cloud service is a type of cloud service that provides access to physical and/or virtual resources in a cloud environment. These services provide a tenant application programming interface (API) that supports operations for manipulating IaaS constructs, such as virtual machines (VMs) and logical networks.
Cloud services typically incorporate monitoring capabilities that monitor service elements. Service elements are often organized in hierarchies to aid logical grouping, physical organization, assignment to security realms, and the like. The service elements can output various metrics that are collected by the monitoring system. In many cases, some mathematical function of a metric is also of interest at various points in the hierarchy above the element on which the metric is measured.